Reverse flow combustors for gas turbine engines are typically constructed out of metal, such as having metallic liner walls for example. Cost and weight requirements have resulted in thin sheet metal being used for combustor liners, however such thin sheet metal combustor liners require significant cooling in order to be able to withstand the high temperature environment to which they are exposed. However, as operating conditions advance, traditional metallic materials are no longer capable of adequately surviving the even higher temperature combustor environments expected.
Ceramic based materials have long been known to offer superior temperature resistance properties relative to comparable metallic materials, however many challenges exist in adapting ceramic materials to gas turbine applications. Ceramic matrix composite (CMC) include woven ceramic fibre within a stiffening ceramic matrix filler, and are known for use in aerospace applications. While CMCs are able to withstand high temperature conditions with little if any cooling required, they are generally difficult to machine and can not easily be formed into the complex shapes often required for aerodynamic reasons in gas turbine engines, for example. Additionally, although strong at high temperatures, CMCs do not posses the thermal growth characteristics of metallic materials, and hence interfaces with adjacent metallic components are difficult to control without causing large thermal mismatch stresses, especially in conditions where temperature varies considerably. Therefore, there remains a need for an improved CMC combustor configuration.